This invention relates to wired networks for transmission of video and/or voice and/or data.
Cable television (CATV) systems generally comprise a head-end facility from which a plurality of trunk lines or main distribution lines emanate in a hub-and-spoke arrangement. Each trunk line serves one or more local distribution networks each of which serves a relatively small number (e.g., about 100 to 250) of end users or subscribers. Each subscriber is connected with one of the trunk lines via a subscriber line that connects with the trunk line at a tap.
CATV systems typically employ 90-volt AC to power main line equipment such as amplifiers and equalizers that are used in the transmission of broadband RF signals from the head-end facility over the various trunk lines to the individual subscribers' facilities (referred to as “forward signals”). Some subscribers may also have equipment such as cable modems that transmit return RF signals back to the head-end facility, and the main line equipment is also used in the transmission of such return signals. The 90-volt AC is carried by each trunk line, but does not go into the subscriber's facilities. The subscriber lines going into the subscribers' facilities typically carry only RF forward and return signals. Thus, devices located along a “drop” between the trunk line tap and a subscriber's facility in current system architectures are limited to being passive devices.
It would be desirable to be able to employ various types of active devices along a drop in a cable system. However, current architectures generally do not allow such usage because of the lack of an available power source for powering active devices